Anybody into home theater stereo? Need a hand

I have a Polk soundbar and subwoofer system.  Its probably 5-6years old now.

Anyways, the last couple weeks the subwoofer has been acting funny.  Sometimes it will randomly thump.  Other times it cuts out.  And it also kinda struggles to work.

The subwoofer is separate unit getting its signal via wireless.  Just a power cord.  It has 4 signal channels (and the soundbar) I am assuming to avoid any potential interference with other devices.  Ive played around with different channels and don't have any improvement.  So I do not think its a signal issue.

Ive pulled the woofer and took a gander inside thinking maybe its a goofy speaker connection.  Nope all seemed solid.

So it must be either the woofer (which feels fine...no binding that I can feel) or the amp.

Any advice?

I am far from the best speaker nerd here (Dr. Boost to the courtesy phone) but to be it sounds like you're getting signal variance from the receiving end, which in my experience is a cabling or terminal issue. Based o  the fact that none of the other components move, id check through the subwoofer and make sure everything is well connected, not corroded and otherwise ready to accept a signal, and work my way back. 

Tl:dr- dr. Boost is way smarter than me at speakers, maybe jiggle the cord and see if it works better. 

It is usually the class d amp that fails.  They don't last long in a sub full of vibrations.  Buy a new one, not worth fixing.

Is there anything that might be causing interference?  Could it be getting phantom signal from something?

It does sound like a problem with the electronics inside the subwoofer. But just to be sure have you tried moving the two parts of the wireless system closer together? 

I agree with previous "sub amp failure" post.  

I wonder if the amp itself could be replaced.  I don't really warm to the idea of wireless for this kind of thing, just seems like needless chance for interference, and over-complication.  If you like projects, you could use the existing sub driver and possibly the enclosure (with some rework) and build a new wired sub out of it with a new amp.  

https://www.parts-express.com/cat/subwoofer-plate-amplifiers/332

1 - call Polk and see what they say

2 - if not fixable, order one of these: (Hsu - I run a pair in the video system)

I agree that its likely the amp and associated electronics.  They are complex.  I had a Definitive sub that gave me problems.  One of the voice coils was about 0.4 Ohms different from the other one and the amp was shutting off and going into protect mode.

The driver itself is a big magnet and coil.  Dirt simple.

I might try swapping out the sub for one borrowed from a friend to make sure it isn't a signal issue, but the real complexity of the system is in the amp and logic parts.  Any one of a hundred things could be causing it there, but the rest of the system is pretty simple.

Does the soundbar even have a wired subwoofer output?  (before you go and spend money on a subwoofer you can't use, or replace the amp yourself or whatnot)

Of course, I'd chuck it *all* myself and go with a proper receiver, speakers and sub, but that's something else entirely.

Yeah, I was wondering what the whole setup for this was.  Is there a stereo receiver in this at all?  If not, is the soundbar connected to your TV or whatever audio signal source is, and you control volume there?  

What kind of budget do you have to fix/replace things?  How much are you willing to change or add on?

Let us help you get this thing spiraling out of control!

The soundbar is double sided taped to the top of my tv.  The sub is not 4ft away on the floor.  The set up and positioning has not changed in the 3 years we lived here.  And it was very similar layout in the prior 2~ years.

Nothing is new or changed in anyway in our house (boring right?)

Like i said its only started acting funny the last 2...maybe 3 weeks.

I have virtually no budget ATM.  Baby on the way and we just bought a new car.

Probably just live with it until I implode and buy a new system.